Yes some/most of that may have been mentioning about The teensy was plugged into one of these. But I mentioned it because maybe Paul had one around... Or maybe more information in the thread about the hub that might give some indication.
Note: My new one did arrive, and for example I ran it connected to the USB Host on a Teensy MicroMod running the Mouse USBHost example sketch.
And so far everything appears to be working.
Code:
USB Host Testing
960
*** Device Hub1 5e3:608 - connected ***
product: USB2.0 Hub
*** Device HID1 46d:c063 - connected ***
manufacturer: DELL
product: DELL USB Laser Mouse
*** HID Device Mouse1 46d:c063 - connected ***
manufacturer: DELL
product: DELL USB Laser Mouse
*** Device HID2 4ca:27 - connected ***
manufacturer: Lite-On Technology Corp.
product: USB Multimedia Keyboard
*** Device KB1 4ca:27 - connected ***
manufacturer: Lite-On Technology Corp.
product: USB Multimedia Keyboard
key 'i' 105 MOD: 0 OEM: C LEDS: 0
key 'f' 102 MOD: 0 OEM: 9 LEDS: 0
key 'a' 97 MOD: 0 OEM: 4 LEDS: 0
key 't' 116 MOD: 0 OEM: 17 LEDS: 0
key ' ' 32 MOD: 0 OEM: 2C LEDS: 0key 'r' 114 MOD: 0 OEM: 15 LEDS: 0
key 's' 115 MOD: 0 OEM: 16 LEDS: 0
key 't' 116 MOD: 0 OEM: 17 LEDS: 0
Mouse: buttons = 0, mouseX = -2, mouseY = 0, wheel = 0, wheelH = 0
Mouse: buttons = 0, mouseX = -8, mouseY = 5, wheel = 0, wheelH = 0
Mouse: buttons = 0, mouseX = -8, mouseY = 3, wheel = 0, wheelH = 0
Mouse: buttons = 0, mouseX = -10, mouseY = 4, wheel = 0, wheelH = 0
Mouse: buttons = 0, mouseX = -11, mouseY = 6, wheel = 0, wheelH = 0
Mouse: buttons = 0, mouseX = -12, mouseY = 6, wheel = 0, wheelH = 0
Mouse: buttons = 0, mouseX = -12, mouseY = 7, wheel = 0, wheelH = 0
Mouse: buttons = 0, mouseX = -13, mouseY = 6, wheel = 0, wheelH = 0
Note: I don't have a midi, so can not test that part...
On your test case, have you tried adding another HUB object to your sketch:
USBHub hub2(myusb);
And see if that helps.
The reason I suggest that is some devices have a built in USB Hub. I have a few keyboards that are built that way. And if there is not a HUB object available, it won't then talk to the actual device, in my case a keyboard.